Advances in medical technology are enabling doctors to identify and treat injuries that went unnoticed 20 years ago. For example, physicians can now use miniaturized television cameras to see inside a joint. With this tool, they have been able to identify and treat a shoulder injury called a glenoid labrum tear.

Anatomy

The shoulder joint has three bones: the shoulder blade (scapula), the collarbone (clavicle), and the upper arm bone (humerus). The head of the upper arm bone (humeral head) rests in a shallow socket in the shoulder blade called the glenoid. The head of the upper arm bone is usually much larger than the socket, and a soft fibrous tissue rim called the labrum surrounds the socket to help stabilize the joint. The rim deepens the socket by up to 50% so that the head of the upper arm bone fits better. In addition, it serves as an attachment site for several ligaments.

Risk Factors/Prevention

Injuries to the tissue rim surrounding the shoulder socket can occur from acute trauma or repetitive shoulder motion. Examples of traumatic injury include:

  • Falling on an outstretched arm
  • A direct blow to the shoulder
  • A sudden pull, such as when trying to lift a heavy object
  • A violent overhead reach, such as when trying to stop a fall or slide
  • Shoulder dislocation or subluxation

Throwing athletes or weightlifters can experience glenoid labrum tears as a result of repetitive shoulder motion.

Symptoms